Implemented video device info for iOS
Implemented video device info for iOS

R=pbos@webrtc.org, tkchin@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/42189004

Patch from Yuriy Shevchuk <youwrk@gmail.com>.

Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#9190}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 39f2b0c870c59dbc37d4f4d8cdb5fff7a7ae5b81

dcpang/fatline-libjingle,dcpang/fatline-libjingle,sippet/talk,dcpang/fatline-libjingle,dcpang/fatline-libjingle,sippet/talk,dcpang/fatline-libjingle,sippet/talk,sippet/talk,sippet/talk